2020 Shoal Lake water quality test results

Our staff test Shoal Lake and the intake at the west end of Indian Bay (where the water enters the aqueduct) as part of our routine water quality testing program.

For more information on Winnipeg's drinking water and our impact on Shoal Lake, visit the web page on Shoal Lake - Our Water Source.

Testing

We take samples at the intake every week during the open water season and every two weeks during the rest of the year. We also take samples from the Shoal Lake watershed from May to October. We test the intake samples for:

• routine water chemistry
• metals
• disinfection by-products
• bacteria and protozoa
• pesticides, herbicides and PCBs

By taking these samples, we track seasonal changes in water quality and determine the effects (if any) of human activity within the Shoal Lake watershed.

Water entering the aqueduct intake passes through screens before being treated by chlorine on a periodic basis for slime and Zebra mussel control. The aqueduct brings water to Deacon Reservoir before entering the Water Treatment Plant. There, we test both the raw and treated water before the water is distributed to Winnipeg homes and businesses.

Test results are from January 1 to December 31, 2020

What is being measured	How it's measured	Shoal Lake average	Shoal Lake range
Miscellaneous
Carbon, Dissolved Organic	parts per million	8.7	6.8 to 11
Carbon, Total Organic	parts per million	8.7	6.6 to 12.7
Chlorophyll-a	parts per billion	4.6	<1.0 to 12.3
Colour, Apparent	TCU	14.3	10 to 23
Colour, True	TCU	8.9	7.5 to 12.5
Conductivity	microsiemens per centimetre	153	144 to 167
Odour	units	92	75 to 150
pH	units	7.88	7.29 to 8.53
Plankton (algae) count	cells/mL	6,668	859 to 17,790
Solids, Total	parts per million	96	71 to 117
Solids, Total Dissolved	parts per million	80	50 to 121
Temperature	degrees Celcius	10.4	1 to 23.9
Turbidity (clearness)	NTU	0.9	0.23 to 5.03
Anions and Nutrients
Alkalinity, Total	parts per million as calcium carbonate	73.7	68.5 to 89.3
Hardness, Total	parts per million as calcium carbonate	76.1	69.8 to 82.2
Chloride	parts per million	1.8	1.3 to 2.1
Fluoride	parts per million	0.08	0.07 to 0.09
Nitrate Nitrogen	parts per million	0.055	0.005 to 0.285
Perchlorate	parts per billion	<0.20	<0.20 to <0.20
Phosphorus, Total Reactive	parts per million	0.0038	<0.0010 to 0.0201
Phosphorus, Total	parts per million	0.0183	0.0092 to 0.034
Sulphate	parts per million	<0.4	<0.4 to 0.4
Total Kjeldahl Nitrogen (TKN)	parts per million	0.52	0.38 to 0.77
Bacteria
Escherichia Coli	MPN per 100 mL	0	0 to 4
Total Coliforms	MPN per 100 mL	88	1 to >200
Disinfection By-Products
Aldehydes	parts per billion	6.7	3.5 to 10.4
Haloacetic acids	parts per billion	<1.2	<1.2 to <1.2
Trihalomethanes	parts per billion	<2.7	<2.7 to <2.7
Enteric Protozoa
Cryptosporidium	oocysts per 100 L	0	0 to 0
Giardia	cysts per 100 L	0	0 to 0
Pesticides
Alachlor	parts per billion	<0.1000	<0.1000 to <0.2000
Aldrin	parts per billion	<0.0100	<0.0100 to <0.0500
alpha-BHC	parts per billion	<0.0100	<0.0100 to <0.0500
alpha-Chlordane	parts per billion	<0.0100	<0.0100 to <0.0500
alpha-Endosulfan	parts per billion	<0.0100	<0.0100 to <0.0500
Atrazine	parts per billion	<0.1000	<0.1000 to <0.2000
Azinphos-methyl	parts per billion	<0.0100	<0.0100 to <0.0200
beta-BHC	parts per billion	<0.0100	<0.0100 to <0.0500
beta-Endosulfan	parts per billion	<0.0100	<0.0100 to <0.0500
Carbaryl	parts per billion	<0.2000	<0.2000 to <0.4000
Carbofuran	parts per billion	<0.2000	<0.2000 to <0.4000
Chlorothalonil	parts per billion	<0.050	<0.050 to <0.050
Chlorpyrifos	parts per billion	<0.0050	<0.0050 to <0.0100
delta-BHC	parts per billion	<0.0100	<0.0100 to <0.0500
Diazinon	parts per billion	<0.0050	<0.0050 to <0.0100
Diclofop-methyl	parts per billion	<0.1000	<0.1000 to <0.2000
Dieldrin	parts per billion	<0.0100	<0.0100 to <0.0500
Dimethoate	parts per billion	<0.1000	<0.1000 to <0.2000
Endrin	parts per billion	<0.0100	<0.0100 to <0.0500
Eptam	parts per billion	<0.200	<0.200 to <0.200
gamma-Chlordane	parts per billion	<0.0100	<0.0100 to <0.0500
Heptachlor	parts per billion	<0.0100	<0.0100 to <0.0500
Heptachlor Epoxide	parts per billion	<0.0100	<0.0100 to <0.0500
Lindane (gamma-BHC)	parts per billion	<0.0100	<0.0100 to <0.0500
Malathion	parts per billion	<0.1000	<0.1000 to <0.2000
Methoxychlor	parts per billion	<0.0100	<0.0100 to <0.0500
Methyl Parathion	parts per billion	<0.1000	<0.1000 to <0.2000
Metribuzin	parts per billion	<0.2000	<0.2000 to <0.4000
Mirex	parts per billion	<0.1500	<0.0100 to <0.1500
o,p-DDD	parts per billion	<0.0100	<0.0100 to <0.0500
o,p-DDE	parts per billion	<0.0100	<0.0100 to <0.0500
o,p-DDT	parts per billion	<0.0100	<0.0100 to <0.0500
p,p-DDD	parts per billion	<0.0100	<0.0100 to <0.0500
p,p-DDE	parts per billion	<0.0100	<0.0100 to <0.0500
p,p-DDT	parts per billion	<0.0100	<0.0100 to <0.0500
Parathion	parts per billion	<0.0130	<0.0130 to <0.0260
Propaclor	parts per billion	<0.200	<0.200 to <0.200
Propanil	parts per billion	<0.200	<0.200 to <0.200
Propoxur	parts per billion	<0.200	<0.200 to <0.200
Simazine	parts per billion	<0.1000	<0.1000 to <0.2000
Terbufos	parts per billion	<0.1000	<0.1000 to <0.2000
Triallate	parts per billion	<0.1000	<0.1000 to <0.2000
Trichlopyr	parts per billion	<0.0500	<0.0500 to <0.0500
Trifluralin	parts per billion	<0.0300	<0.0300 to <0.0600
Polychlorinated Biphenyls
Arochlor 1016	parts per billion	<0.0200	<0.0200 to <0.0200
Arochlor 1221	parts per billion	<0.0200	<0.0200 to <0.0200
Arochlor 1232	parts per billion	<0.0200	<0.0200 to <0.0200
Arochlor 1242	parts per billion	<0.0200	<0.0200 to <0.0200
Arochlor 1248	parts per billion	<0.0200	<0.0200 to <0.0200
Arochlor 1254	parts per billion	<0.0200	<0.0200 to <0.0200
Arochlor 1260	parts per billion	<0.0200	<0.0200 to <0.0200
Phenoxy Acid Herbicides
2,4,5-T	parts per billion	<0.5000	<0.5000 to <0.5000
2,4,5-TP	parts per billion	<0.5000	<0.5000 to <0.5000
2,4-D	parts per billion	<0.5000	<0.5000 to <0.5000
2,4-DB	parts per billion	<0.0500	<0.0500 to <0.0500
2,4-DP	parts per billion	<0.5000	<0.5000 to <0.5000
Bromoxynil	parts per billion	<0.5000	<0.5000 to <0.5000
Dicamba	parts per billion	0.0073	<0.0060 to 0.0105
Dinoseb	parts per billion	<0.5000	<0.5000 to <0.5000
MCPA	parts per billion	<0.5000	<0.5000 to <0.5000
MCPB	parts per billion	<0.0500	<0.0500 to <0.0500
Mecoprop	parts per billion	<0.5000	<0.5000 to <0.5000
Picloram	parts per billion	<0.5000	<0.5000 to <0.5000
Total Metals
Aluminum	parts per million	0.00269	0.00127 to 0.0051
Antimony	parts per million	0.000385	<0.000025 to 0.00018
Arsenic	parts per million	0.000751	0.00064 to 0.000891
Boron	parts per million	0.00368	<0.00208 to 0.00652
Cadmium	parts per million	<0.000007	<0.000007 to <0.000007
Calcium	parts per million	19.6	17.529 to 23.74
Chromium	parts per million	<0.00004	<0.00004 to 0.00007
Chromium VI	parts per million	<0.00050	<0.00050 to <0.00050
Copper	parts per million	0.001455	0.000638 to 0.00337
Iron	parts per million	0.04409	0.01288 to 0.17963
Lead	parts per million	<0.000065	<0.000065 to 0.000085
Magnesium	parts per million	6.015	5.329 to 7.163
Manganese	parts per million	0.01	0.00285 to 0.03359
Mercury	parts per billion	<0.0050	<0.0005 to <0.0050
Nickel	parts per million	0.000098	<0.000021 to 0.000191
Potassium	parts per million	1.232	1.064 to 1.521
Sodium	parts per million	2.228	2 to 2.669
Uranium	parts per million	<0.000032	<0.000032 to 0.000036
Zinc	parts per million	0.0011	0.00035 to 0.00236

Note: Where value is expressed as less than (<), the value is halved and used in the calculations, where value is expressed as (>), the value is used in the calculations.

Guidelines for Canadian Drinking Water Quality do not apply to Shoal Lake